<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        let arr = [1,2,4,5,'abc'];
        // let arr1 = arr.map(function (item) {
        //     return item*2
        // });
        let arr1 = arr.map(s=>s+6)
        alert(arr1)
    </script>
</head>
<body>

</body>
</html>